The municipality of Jurisdicción de Lara (51 inhabitants in 2009; 2,516 ha; municipal website) is located in the southeast of the Province of Burgos, 45 km of Burgos. The municipality is made of the villages of Aceña de Lara (aka La Aceña, 8 inh.), Lara de los Infantes (26 inh.) and Paúles de Lara (17 inh.).

The medieval group of villages known as the Alfoz de Lara is considered as the "Cradle of Castile." Lord Gonzalo Fernández built the Picón de Lara castle on a rock dominating the village of Lara de los Infantes, then located on the border with the Muslim states. Gonzalo's sun, Fernán González, probably born in the castle, was mentioned in 931 as the Count of Burgos, Castile, Asturias de Santillana, Lara, Lantarón, Cerezo and Álava. An influent member of the court of King of León Ramiro II, Fernán González helped the king to defeat the Moors in the Battle of Simancas; accordingly, Fernán resettled the reconquerred territories and married Sancha, the sister of King of Navarre García Sánchez. Fernán González set up an autonomous domain and is therefore considered as the first independent Count of Castile. The tradition says that Fernán González' first official act was the reestablishment of the former Visigothic monastery of Quintanilla de las Viñas, located near Lara; the event is considered as the symbolic beginning of the Christian reconquest.
The House of Lara was a noble Castilian lineage; some say they descend from the Counts of Castile, also Counts of Lara, but other say that they descend from Gonzalo Núñez (c. 1052-1104?), the first known lord of the alfoz of Lara. Its members played a key role in the history of the Kingdoms of Castile and León in the 11th-14th century. They were subsequently survived by the Manrique de Lara branch, raised in 1520 by King Charles I as Grandees, Dukes of Nájera and Marquis of Aguilar de Campoo.

The flag and arms of Jurisdicción de Lara are prescribed by a Decree adopted on 17 February 2004 by the Municipal Council, signed on 1 October 2004 by the Mayor, and published on 15 October 2004 in the official gazette of Castilla y León, No. 200, p. 14,820 (text).
The symbols are described as follows:

Flag: Rectangular with proportions 2:3, made of a panel formed by three equal vertical stripes, the middle red and the outer white, in the middle the municipal coat of arms.Coat of arms: Argent a pale gules charged with an eagle argent crowned or and a castle or masoned sable port and windows azure surrounded dexter with two cauldrons sable per pale and sinister with a lion gules. The shield surmounted with a Royal Spanish crown.

"Argent two cauldrons sable per pale" are the traditional arms of the House of Lara. The cauldrons represent the great numbers of vassals that the Counts of Lara could call - and feed -, when required.

Aceña de Lara (aka La Aceña de Lara; village
monograph) was first mentioned on a document dated 1 April 1312, as part of the alfoz (group of villages) of Lara.
The village is named for the Arabic word seniya, meaning "a noria, a
vertical wheel". Three grain mills, powered by river Valpoza, are
indeed documented, two upstream the village and a third one,
downstream, on the road connecting Lara and Campolara. Madoz listed
one grain mill and two fulling mills operated in winter only. The
local tradition says that the settlement at the origin of Aceña is the village of Fuentelpuerco, located 800 m north-east of the today's
village and for long disappeared. The aforementioned document lists
the settlement of Fuenteasur.
Aceña was recorded in 1591-1592 as a Royal town, part of Lara, which
had been incorporated to the alfoz of Burgos long before. In the
19th century, the village counted 42 inhabitants, producing different
crops, "delicious fruit" included, and charcoal sold in Burgos and the
neighbouring towns.

The flag and arms of Aceña de Lara, approved in 15 July 2004 by the Village Council, are prescribed by a Decree adopted on 4 November by
the Village Council, signed on 11 December 2004 by the Mayor, and
published on 5 January 2005 in the official gazette of Castilla y León, No. 3, p. 320 (text).
The symbols are described as follows:

Flag: Rectangular in proportions 2:3, made of two horizontal stripes. The first stripe, red, with a height of 2/3 of the flag's height,
shall be charged in the center with a white millstone, of diameter 60%
of the stripe's height. The second stripe, with a height of 1/3 of the
flag's height, shall be horizontally divided in five equal stripes:
white, blue, white, blue, and white.Coat of arms: Gules (red) a millstone argent in base waves argent and azure (blue). The shield surmounted with a Royal crown closed.

The flag and arms of Paúles de Lara, adopted on 1 March 2005 by the Village Council, are prescribed by a Decree adopted on 10 August 2005
by the Village Council, signed on 3 June 2006 by the Mayor, and
published on 12 June 2006 in the official gazette of Castilla y León, No. 112, p. 11,199 (text).
The symbols are described as follows:

Flag: 1:1, quadrangular and tricolor. Upper left corner (0.5 vertical and 0.4 horizontal), red. Lower left corner in the same dimensions, yellow. The rest of the flag white. In the center of the field the municipal coat of arms.Coat of arms: Per pale, 1. Gules a calvary argent in chief dexter the arms of Castile or, 2. Or an oak eradicated in base two spots azure.
The shield surmounted with a Royal crown closed.